1. Field of the Invention
The present invention relates to the preparation of shaped catalyst supports or catalysts, per se, based on titanium oxide, and to the use thereof for Claus catalysis.
2. Description of the Prior Art
Various processes are of course well known to this art for the preparation of shaped supports or catalysts based on titanium oxide, but such known processes are characterized by the disadvantages of providing final products which are lacking in mechanical strength and are otherwise wholly unsatisfactory from a textural point of view.
It has been proposed, according to published French Patent Application No. 2,336,177, to prepare catalysts or supports based on titanium oxide by calcining, at 200.degree.-800.degree. C., that starting material consisting of titanium oxide or a substance or precursor which can be converted to titanium oxide, in the presence of a metatitanic acid sol or gel. However, this process has been demonstrated to provide products, the specific surface area of which does not exceed about 50 m.sup.2/g and also of which pore volume, pore size distribution and mechanical strength too are not satisfactory. In particular, the process described in said published French Patent Application No. 2,336,177 does not permit control over the pore structure of the ultimate product in a simple or even effective manner. Furthermore, this process requires the use of a metatitanic acid sol or gel, which makes the process complicated and difficult to carry out.
Furthermore, it has also been proposed, according to U.S. Pat. No. 4,061,596, to prepare shaped catalyst supports based on titanium oxide by calcining titanium oxide at 400.degree.-800.degree. C. and then shaping the product and calcining the shaped product at 300.degree.-800.degree. C. This particular process provides supports, consisting of titanium oxide, the specific surface area of which does not exceed about 80 m.sup.2 /g and of which pore volume, pore size distribution and mechanical strength remain unsatisfactory.